/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/ClusterUnionManager.h
Actually performs the change specified in the FClusterUnionOperationData structure.
void HandleAddOperation ( [FClusterUnionIndex](API\Runtime\Chaos\Chaos\FClusterUnionIndex) ClusterIndex, const [TArray](API\Runtime\Core\Containers\TArray)< [FPBDRigidParticleHandle](API\Runtime\Chaos\Chaos\FPBDRigidParticleHandle) * > & Particles, bool bReleaseClustersFirst )